Nowadays, touch devices are widely used in many fields such as personal computers, smart phones, smart appliances, industrial control, and so on. Types of touch sensor, such as resistive touch sensor, photoelectric touch sensor, acoustic touch sensor, surface capacitive touch sensor, and projected capacitive touch sensor, can be used in electronic devices.
In the current technology, an acoustic wave generator of an acoustic touch device sends a high-frequency acoustic wave to a top surface of a cover. When a finger is touching the cover, a portion of the acoustic wave can be blocked by the finger, and a portion of the acoustic wave can be reflected and be received by an acoustic wave receiving element, and the acoustic wave receiving element receives the reflected acoustic wave and converts it into an electrical signal. A controller analyzes the electrical signal, and the controller determines whether the touch signal is effective. However, other factors (such as water, oil, and the like) on the acoustic touch device may affect the electrical signals of the acoustic wave receiving element, and it may be rendered difficult for conventional acoustic touch devices to distinguish a finger's touch, which may lead the acoustic touch device to wake up frequently and cause increased power consumption.